Welcome to the Winobloggers webpage! Students and professors from different universities meet to discuss their findings on Winogradsky columns they constructed!
We learn how to formulate hypotheses, observe, comment, ask and reply to questions related to our scientific experiments.

Winogradksy columns

Blog posts

Friday, 8 April 2016

As both bottles
have been in the same conditions, they have a similar appearance. We will
describe them as a whole.

On the water surface we can observe tiny white
algae attached to the bottle. As we descend in the liquid region of the column,
we encounter some small snails that possibly feed on the algae mentioned
before, as they have survived for 2 weeks.

The soil’s surface is covered by another type
of algae. They are long and white, with a filamentous appearance, presenting
bubbles along their structure.

We decide to divide the soil region in 3 equal
parts, as shown in the next picture

- - In the top layer, S1, we find zones with an
intensive orange colour all around and small black clusters in the part of the
bottle that wasn’t exposed to direct sunlight. However, we can’t observe any
changes to the other side, due to it being in direct sunlight. There is also a
great amount of air trapped in the layer. Our hypothesis for the orange
colouring is that it is red or purple
photosynthetic bacteria.

- - In the middle layer, S2, the concentration of
orange zones reduces as we descend in the column. On the other hand, the black
clusters become more numerous and grow in size.

- - In the bottom layer, S3, we can only
distinguish black colonies, with an exception in the border that separates the
light and dark zones, where we can still find small orange layers. We think
that these black clusters are formed by the H2S produced by sulphur reducing bacteria. As we can’t
find orange zones within these clusters, we suppose that H2S is
toxic to photosynthetic bacteria